JP4542816B2 - Curtain type coater - Google Patents

Abstract

Curtain coater has caper head (3) with slot (s2) at edge which is broadly framed than the other part of slot (s1). The widened slot is arranged in a distance from the edge side of the caper head. Broader slot has different shape such as rectangle, circle or oval. The caper head is built up from two caper bodies (3b). The broader part of the slot has a width dimension double of the other slot. The slots are provided at the caper head for track spacing purpose.

Description

      The present invention relates to a curtain type coater for applying a paint to a web such as paper from above.

    2. Description of the Related Art Conventionally, coated paper used for catalogs, thermal paper, automatic ticket gates, and the like has been made by applying a coating liquid onto the surface of a web that is a base paper.

  A machine for applying such a coating liquid is generally referred to as a coating machine, and a coating machine that applies a coating liquid from above to a web such as paper among the coating machines is referred to as a curtain coater. .

  As shown in FIG. 6 (a), the curtain coater 100 applies a predetermined thickness of coating liquid onto the web surface, so that the web upper surface (FIG. 6 (a)) is conveyed in the direction perpendicular to the paper surface. (Not shown), the coating liquid t in the head body 101 is ejected from above into a curtain tc shape.

  In this curtain coater 100, although it varies depending on the type of the coating liquid t, in general, in the case of a curtain tc having a low flow rate of 6 to 7 liters / minute / meter width or less, as shown in FIG. The edge portion ce of the curtain tc is pulled inward by the surface tension directed inward, and the curtain tc of the coating liquid t becomes unstable.

  In order to solve this problem, in the curtain type coater 200 shown in FIG. 7, guide bars gb or guide plates are arranged at both ends of slits (not shown) that are jet outlets of the coating liquid t in the head body 201. The curtain tc of the coating liquid t is guided to prevent the curtain from becoming unstable.

As a prior art document related to the present application, Patent Document 1 which is a known document is disclosed.
JP-A-8-1061

    As described above, in the general curtain coater 100, when the sprayed coating liquid t has a low flow rate, the edge portion ce of the curtain tc is pulled inward by the surface tension, and the curtain tc of the coating liquid t It becomes unstable.

  Further, when the flow rate is further reduced, the curtain tc becomes mottled and exhibits a raindrop state, making it difficult to maintain a predetermined coating performance.

  In order to solve this problem, a flow rate of the coating liquid t of a certain amount or more is necessary, and there is an inconvenience that an extra coating liquid t has to be used.

  On the other hand, in the curtain coater 200 provided with the guide bar gb or the guide plate, when the coating operation is continued for a long time, the coating liquid t adheres to the guide bar gb and the guide plate and is solidified by drying. The curtain tc is disturbed and the guide function is impaired.

  Further, the guide bar gb and the guide plate interfere with a color pan (not shown) for receiving the coating liquid at the start of coating, and the curtain tc of the coating liquid t is disturbed, causing a problem.

  In addition, when the guide bar gb and the guide plate are provided, it becomes a hindrance during various operations such as maintenance, leading to a decrease in workability.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to provide a curtain type coater that can stabilize a coating liquid curtain with a simple configuration, has high coating performance, and requires a small amount of coating liquid to be used.

In order to achieve the above object, a curtain type coater according to claim 1 of the present invention sprays coating liquid from a slit of a curtain head from above the web being conveyed and the outside of both ends of the web. A curtain type coater for forming a liquid curtain and applying a coating liquid to the upper surface of the web, wherein the curtain head includes a first lip provided on the outer side of both ends of the web and facing each other. Including a second lip, and a part of the slit is formed between the first lip and the second lip facing each other, and the first lip and the second lip Thus part formed of the slit is extensively formed from elsewhere out of the slit, said first lip and at least in part, Bol for inserting bolts of the second lip A lip in which a bolt hole is formed among the first lip and the second lip is supported on the curtain head body by a bolt inserted into the bolt hole, and the slit is formed. Of these, the width of the part formed widely is supported so as to be adjustable by the bolt .

A curtain type coater according to claim 2 of the present invention is the curtain type coater according to claim 1, wherein at least one of both end portions of a slit formed between the first lip and the second lip. Kano end, is characterized in that it is formed wider than other portions of the slit.

Curtain coater according to claim 3 of the present invention, the curtain coater according to claim 1 or claim 2, a portion of said widely formed among the slits, the other slit portion more than double the It is characterized by having a width dimension.

    As described above in detail, according to the curtain type coater according to claim 1 of the present invention, the coating formed on the upper surface of the web with respect to the slit for ejecting the coating liquid curtain formed on the upper surface of the web. Since at least a part of the slit that ejects the working liquid curtain is widely formed, the flow rate of the coating liquid curtain from the wide slit on the upper surface of the web increases, and the coating liquid facing inward in the coating liquid curtain increases. The influence of the surface tension is reduced, and the coating liquid curtain on the web upper surface is prevented from being disturbed.

  Therefore, a stable coating liquid curtain can be obtained at a low flow rate, and a curtain type coater with high coating performance and a reduced flow rate of the coating liquid can be realized.

  According to the curtain type coater according to the second aspect, since the slit of the curtain head is formed so that at least one of the end portions thereof is wider than the other portion, the width of the curtain type coater can be reduced.

  According to the curtain type coater according to the third aspect, the widely formed slit has a width dimension more than twice the width of the other slits, so that the flow rate of the coating liquid becomes a certain amount or more, and the coating liquid curtain ejection direction Thus, a more stable coating liquid curtain can be obtained.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  The curtain coater 1 according to the first embodiment of the present invention conveys a web 2 as a base paper in the direction of arrow α at a speed of 100 to 2000 meters / minute as shown in FIG. In this way, the coating liquid t is applied to the upper surface of the web 2.

  As shown in FIG. 1B, the curtain coater 1 is applied to a coating liquid supply port tk supplied to a chamber (described later) of the curtain head 3 as shown in FIG. The liquid t is inserted through the slit s1 and the wide slits s2 and s2 toward the upper surface of the web 2 to be conveyed and ejected in a curtain shape to form the coating liquid curtains tc1 and tc2, thereby forming the upper surface of the web 2 A coating liquid layer having a predetermined thickness, for example, 10 to 50 μm is formed thereon.

  This curtain type coater 1 is characterized in that the coating liquid that is part of the coating liquid curtain on the top surface of the web 2 and the thickness mc1 = 0.3 mm inside the coating liquid curtain tc1 on the top surface of the web 2. The thickness mc2 of the curtain ends tc2 and tc2 is set to 1 to 3 mm, and the flow rate at both ends tc2 and tc2 of the coating liquid curtain is increased from the inside tc1 of the coating liquid curtain. The coating liquid curtain tc is stabilized against the surface tension of the coating liquid t facing inwardly applied to tc2 and tc2.

  With this configuration, the curtain coater 1 enables a predetermined coating performance with a low flow rate of the coating liquid t.

  Next, the configuration of the curtain coater 1 will be described.

  As shown in FIG. 1, the coating liquid t ejected from the slits s 1 and s 2 of the curtain head 3 forms coating liquid curtains tc 1 and tc 2 and applies a coating liquid of a predetermined thickness on the upper surface of the web 2. At the same time, the surplus coating liquid t ejected outside the upper surface of the web 2 and not applied is collected by the color pan kp shown in FIG.

  The recovered coating liquid t is returned to a tank (not shown), and is circulated by applying a predetermined pressure with a pump together with a newly supplied coating liquid t. It is sent again through the coating liquid supply port tk to the chamber 3c of the curtain head 3 (see FIG. 2A, which is a sectional view taken along the line BB of the curtain head in FIG. 1B).

  The coating liquid t sent to the chamber 3c is inserted into the slits s1 and s2 and ejected toward the upper surface of the web 2 in the form of curtains tc1 and tc2, and is used for coating the upper surface of the web 2.

  As shown in FIG. 1B, the curtain head 3 includes a head body 3b, packings 3p and 3p for sealing the head body 3b to prevent leakage of the coating liquid t, and the packing 3p, End plates 3e and 3e for closely supporting 3p on the head body 3b are provided.

  As shown in FIG. 2 (c), which is a bottom view of the curtain head of FIG. 1 (b), the curtain head 3 has a coating liquid having a width dimension ms1 = 0.3 mm provided in the head bodies 3b1, 3b2. The slit s1 for forming the curtain interior tc1 and the slits s2 and s2 for forming the coating liquid curtain end portions tc2 and tc2 having a width dimension ms21 = 1 to 3 mm provided in the packings 3p and 3p are provided.

  Here, it is confirmed that the width dimension ms21 of the slit s2 is preferably 0.6 mm or more, and most preferably 1 to 3 mm, with respect to the width dimension ms1 = 0.3 mm of the slit s1.

  Thus, by making the width dimension ms1 of the slit s1 different from the width dimension ms21 of the slit s2, the flow rate at both ends tc2 and tc2 of the coating liquid curtain is made larger than the flow rate inside the coating liquid curtain tc1. .

  In the present embodiment, the case where the width dimension ms1 of the slit s1 is set to 0.3 mm is illustrated, but it is also possible to set the width dimension to 0.2 to 0.5 mm. The width dimension ms21 of the slit s2 can be appropriately selected according to coating conditions such as the thickness of the coating liquid layer applied on the web 2.

  As shown in FIGS. 2A and 2C, the head body 3b includes a first head body 3b1 and a second head body 3b2 that form a main body, and a first head body 3b1 and a second head body 3b2. And a first lip 3l1 and a second lip 3l2 for adjusting the width of the slit s1.

  The first head body 3b1 and the second head body 3b2 are made of, for example, stainless steel. As shown in FIGS. 1B and 2C, the chamber 3c having a predetermined shape and a constant width of 0.3 mm are used. Each of the slits s1 is provided with a notch that forms one side of the slit s1, and is manufactured in a long shape corresponding to the web 2 width, for example, 1 to 5 m or more.

  The first lip 3l1 and the second lip 3l2 are made of, for example, stainless steel, and as shown in FIG. 2 (a), a part of a slit s1 having a width of 0.3 mm is formed, and a slit width adjusting bolt (see FIG. A hole through which (not shown) is inserted is drilled.

  The packings 3p and 3p shown in FIG. 2 (b), which is a cross-sectional view taken along the line C-C of FIG. 1 (b), are rubber products made of, for example, butadiene rubber or the like. As shown in FIG. A slit s21 having a width dimension ms21 = 1-3 mm distributed around the slit s1 of the bodies 3b1, 3b2, and a slit s22 having the same width dimension ms22 = 0.3 mm arranged in parallel to the slit s1 of the head bodies 3b1, 3b2. Are formed, and a hole 3p1 corresponding to the chamber 3c of the head body 3b is formed.

  As described above, the width dimension ms21 of the slit s21 in the slit s2 is larger than 1 to 3 mm and the width dimension ms1 (= 0.3 mm) of the slit s1, so that the cross-sectional area becomes larger than the slit s1, and the slit s2 is slit. The coating liquid t having a flow rate larger than s1 is flowed, and the thickness of the coating liquid curtains tc2 and tc2 from the slit s2 is larger than the thickness of the coating liquid curtain tc1 from the slit s1.

  Here, in the above-described example, as shown in FIG. 2B, the widened portion s21 of the slit s2 provided in the packing 3p is formed inward from the slit opening s2k in a part of the entire length of the slit s2. Although illustrated, if it is formed inward from the slit opening s2k, it may be formed over the entire length of the slit s2, or may be formed in part as in this embodiment.

  According to the above configuration, as shown in FIGS. 1 (b) and 2 (c), on the top surface of the web 2 with respect to the width of the slit s1 on the inside of the coating liquid curtain tc1 formed on the top surface of the web 2. By increasing the widths of slits s2 and s2 at both ends tc2 and tc2 of a part of the slit of the slit forming the outer coating liquid curtain, the flow rate of the coating liquid curtain ends tc2 and tc2 is increased. The increase in weight reduces the influence of the inward surface tension applied to the coating liquid curtain ends tc2, tc2, and prevents the coating liquid curtain ends tc2, tc2 from being pulled inward.

  Therefore, the coating liquid curtain is prevented from being disturbed, the coating liquid curtain is stabilized, and a stable and high-quality coating operation can be performed.

  Moreover, since the coating liquid curtain is stabilized by increasing the flow rates at both ends tc2 and tc2 of the coating liquid curtain, the total flow rate of the coating liquid tc1 can be reduced.

  For example, in order to obtain a predetermined coating performance, conventionally, a flow rate of 7.4 liters / minute / meter width is required. However, the width dimension ms1 of the slit s1 forming the coating liquid curtain inside tc1 on the upper surface of the web 2 = When the width dimension ms21 of the slit s2 forming the coating liquid curtain ends tc2 and tc2 which are a part of the coating liquid curtain on the upper surface and the outer surface of the web 2 is set to 3 mm, 5 mm is obtained. It has been confirmed that the flow rate can be reduced to 4 liters / minute / meter width.

  Also, if the flow rate at both ends tc2 and tc2 of the coating liquid curtain is increased, the contraction flow at both ends of the curtain is small, so that the coating liquid curtain can be stabilized with the narrowest dimension, and the curtain type coater The overall width dimension of the can be reduced as much as possible.

  Therefore, the curtain type coater can be realized with a simple configuration, the stabilization of the coating liquid curtain, high coating performance, and low flow rate.

  Therefore, the field of application of the curtain coater can be expanded, and a wide range of uses can be obtained for the curtain coater.

  As shown in FIG. 3A and FIG. 3B of the enlarged bottom view of the curtain head 23 in FIG. 3A, the curtain coater 21 according to the second embodiment of the present invention has a packing 23p in the curtain head 23. 23p, slits 2s1 and wide slits 2s2, 2s2 are formed only in the head body 23b without forming slits.

  In this configuration, the coating liquid t is ejected onto the upper surface of the web 22 through the slit 2s1 of the head body 23b to form the inside 2tc1 of the coating liquid curtain. The coating liquid curtain ends 2tc2 and 2tc2 are formed by jetting the coating liquid t through the slits 2s2 and 2s2 to form the coating liquid curtain ends 2tc2 and 2tc2 at a high flow rate, thereby stabilizing the coating liquid curtains 2tc1 and 2tc2. Work performance is secured.

  In order to form the coating liquid curtain interior 2tc1, the curtain type coater 21 has a first head body as shown in FIG. 3C of the sectional view taken along the line DD of the curtain head 23 of FIG. A chamber 23c through which the coating liquid t is fed is formed in 23b1 and the second head body 23b2, and a slit 2s1 having a width dimension ms1 is formed in communication with the chamber 23c.

  The first head body 23b1 and the second head body 23b2 support the first lip 23l1 and the second lip 23l2, respectively, or one of the two lips by an adjustment bolt so as to be adjustable. A slit 2s1 is formed in the first lip 23l1 and the second lip 231l continuously to the slit 2s1 of the first head body 23b1 and the second head body 23b2.

  On the other hand, as shown in FIG. 3A, in order to form the coating liquid curtain end portions 2tc2 and 2tc2 formed on the upper surface and the outer surface of the web 22, the E− of the curtain head 23 in FIG. As shown in FIG. 3 (d), which is a cross-sectional view taken along line E, the first head body 23b1 and the second head body 23b2 are arranged in parallel with the slit 2s1 in communication with the chamber 23c and have the same width as the width dimension ms1. A slit 2s22 having a dimension ms22 is formed.

  The first lip 23l1 and the second lip 23l2 that are supported by the first head body 23b1 and the second head body 23b2 by adjusting bolts, respectively, have slits 2s22, the first head body 23b1 and the second head. A slit 2s21 having a width dimension ms21 obtained by enlarging the width of the slit 2s22 and the width of the slit 2s22 is formed below the slit 2s22 of the body 23b2.

  Here, when the width dimension ms1 of the slit 2s1 of the coating liquid curtain 2tc1 is 0.3 mm, the width dimension ms2 of the slits 2s2 and 2s2 of the coating liquid curtain both ends 2tc2 and 2tc2 is at least 0.6 mm. It is necessary to set it as the above, and when it is 1-3 mm width, it is more suitable.

  Also in the configuration of the second embodiment, the same operational effects as the first embodiment are obtained.

  Next, modified examples 1 and 2 of the second embodiment will be described with reference to FIG.

  In the second embodiment described above, as shown in FIG. 3B, when the slits 2s2 and 2s2 forming the coating liquid curtain both ends 2tc2 and 2tc2 are widened, only the first head body 23b1 is widened. Although illustrated, the curtain head 23 ′ of the first modification is assigned the same dimension m 3 to the first head body 23 b 1 ′ and the second head body 23 b 2 ′ as shown in FIG. Wide slits 2s2 'and 2s2' are formed at both ends.

  In the modification 1, the case where the slits 2s2 'and 2s2' are provided symmetrically with respect to the joint surface between the first head body 23b1 'and the second head body 23b2' is illustrated, but it is not necessarily provided symmetrically. Also good.

  Further, the curtain head 23 ″ of the modified example 2 has a wide slit 2s2 ″, 2s2 for forming a thick portion of the coating liquid curtain as shown in FIG. ″ Is provided at a location separated from the edges of the first head body 23b1 ″ and the second head body 23b2 ″ by a dimension m4.

  As described above, the wide slits 2s2 ″ and 2s2 ″ are not necessarily formed at both ends of the coating liquid curtain, and may be formed at locations other than both ends of the coating liquid curtain.

  That is, the position of the widened slit in the curtain head is outside the upper surface of the web 2 as shown in FIGS. 1 (b) and 3 (a), and if the coating liquid curtain is prevented from being disturbed, The position is not particularly limited.

  In the first and second embodiments, the case where the slits are widened on both sides outside the upper surface of the web is illustrated. However, even if the slits are provided only on one side outside the upper surface of the web, certain effects can be obtained.

  Further, the widened slit may be provided in the first head body and the second head body, or may be provided in a packing for sealing the head body as in the first embodiment, or alternatively, the head body and the packing may be provided. It is also possible to provide them continuously, and the member that provides the widened slit can be arbitrarily selected.

  In the first and second embodiments, the case where the cross-sectional shape of the wide slit is a quadrangle is illustrated, but the cross-sectional shape of the wide slit 2s2 shown in FIG. 3 (b) is shown in FIG. 5 (a). The cross-sectional shape of the wide slit 2s2 'shown in FIG. 4 (a) may be the round shape shown in FIG. 5 (b), and similarly FIG. The cross-sectional shape of the wide slit 2s2 ″ shown in FIG. 5 may be circular as shown in FIG.

  Thus, if the cross-sectional shape of the wide slit has a dimension such that the film thickness of the coating liquid curtain to be formed is more than twice the film thickness of the coating liquid curtain formed by the other slits, Other cross-sectional shapes such as a rectangular shape and an elliptical shape other than the round shape shown in the examples can also be adopted.

    Application examples of the present invention include a coating machine for applying paint to a calendar, catalog, thermal paper, pressure sensitive paper, etc., or a coating machine for applying a magnetic material to one side of a ticket for an automatic ticket gate, etc. If it is a coating machine that applies a coating liquid or the like to the web surface, its application range is not particularly limited and can be widely applied.

(a) And (b) is a conceptual diagram which shows the coating operation | work of the curtain type | mold coater of Example 1 in connection with this invention, and (a) A direction arrow directional view of a figure. (a), (b), and (c) are sectional views taken along the line BB of the curtain head in FIG. 1 (b), the sectional view taken along the line CC in FIG. 1 (b), and FIG. The bottom view which shows the curtain head in a curtain type coater. (a), (b), (c), and (d) are diagrams showing a coating operation of the curtain coater of Example 2 according to the present invention, and show a curtain head in the curtain coater of FIG. A bottom view, a DD line sectional view of the curtain head of Drawing (a), and an EE sectional view of the curtain head of Drawing (a). (a) And (b) is the bottom view which shows the modification 1 of the curtain head of Example 2 in connection with this invention, and the bottom view which shows the modification 2. FIG. (a), (b), and (c) are the bottom views of the curtain head which show the example of a change of the cross-sectional shape of the widened slit of Example 1, 2, respectively. (a) And (b) is a figure which shows the coating operation | work of the conventional curtain type | mold coater, and the figure which shows the coating operation | work in case the coating liquid is a low flow rate in the curtain type | mold coater of (a) figure. The figure which shows the coating operation | work of the curtain type coater which has the conventional guide plate.

Explanation of symbols

1, 21 ... Curtain type coater,
2, 22 ... Web,
3, 23, 23 ', 23 "... curtain head,
s1, 2s1, 2s1 ', 2s1 "... slit,
s2, 2s2, 2s2 '... the end of the slit (a wide slit),
2s2 ″… Slit formed widely,
tc1, tc2, 2tc1, 2tc2 ... coating liquid curtain,
tc1, 2tc1 ... coating liquid curtain formed on the upper surface of the web,
tc1, tc2, 2tc1, 2tc2,... coating liquid curtain formed outside the upper surface of the web,
tc2, 2tc2 ... thick coating liquid curtain among the coating liquid curtain outside the top surface of the web,
t: Coating liquid.

Claims (3)

Curtain type coater that forms a coating liquid curtain by spraying a coating liquid from the slits of the curtain head from above the conveyed web and the outside of both ends of the web, and applies the coating liquid to the upper surface of the web Because
The curtain head includes a first lip and a second lip provided opposite to each other above the outer ends of the web,
A part of the slit is formed between the surfaces of the first lip and the second lip facing each other,
It said portion of the first lip and the second of said slits Thus formed lip, broadly formed than elsewhere among the slits,
A bolt hole for inserting a bolt is formed in at least one of the first lip and the second lip,
Of the first lip and the second lip, a lip in which a bolt hole is formed is supported on the main body of the curtain head by a bolt inserted into the bolt hole, and is formed widely in the slit. A curtain type coater characterized in that a part of the width is supported by the bolt so as to be adjustable . Claims wherein at least one of the end portions of the both end portions of the slits formed between the first lip and the second lip, and characterized in that it is from the widely formed elsewhere of the slit The curtain type coater according to 1. Curtain coater according to claim 1 or claim 2 portion of said widely formed is characterized by having more than double the width of the other slit portion of the slit.

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